Packaging of bottles is performed by known automatic machines, in which the bottles are fed on a conveying line, so as to be progressively taken to different work stations and then conveyed to the machines outlet.
In a rejection station, usually situated upstream of the outlet, the bottles considered faulty due to a certain reason, are separated from the remaining ones, so that only the bottles, which have selected characteristics, arrive to the outlet.
The means for defining the rejection station are obtained in relation to the intended rejection criteria, which depend on the nature of the product introduced into the bottles, on the intention or non-intention to re-cycle the product, on the material of which the bottles are made and on other factors, which can become essential on occasion.
In particular, when packaging pharmaceutical products into glass bottles, the following conditions must be ensured:                1. control of the “identity” of each bottle, so that the rejection is directed, without doubts, to the faulty bottle.        2. no faulty bottle can remain together with the good ones and be conveyed therewith to the outlet, even in case of malfunction of the means handling the bottles in the rejection station.        3. protection of the integrity of the rejected bottles, so as to allow the re-cycling of the product, which can be very expensive and/or to avoid the contamination of the environment and operators by the product.        
The constructive solutions used so far to obtain work means of the rejections stations are not sufficient to ensure the above mentioned conditions.
In some cases, possible operation failures, even sporadic, cannot be accepted.